This invention relates to a supply system particularly but not exclusively a supply system wherein hazardous chemicals in liquid form can be supplied from a storage tank of the system to associated dispensing equipment.
Known supply systems include a storage tank in which the chemical is stored temporarily before dispensing, pipework leading from the storage tank to the dispensing equipment, and a pump for pumping the chemical through the pipe-work, the pump being located at a position between the tank and the dispensing equipment.
Other equipment, for example, a diverter valve or other valve structure and monitoring sensors may be positioned in the pipe-work between the tank and the dispensing equipment. Pumps, diverter valves, and similar devices using moving parts accessible to the liquid chemical are prone to leakage arising from seal wear or seal failure, and this problem is exacerbated by chemicals which are aggressive to the seal material or not compatible with seal lubricants. Naturally chemical leaks into the working environment are undesirable and where certain chemicals are concerned, such leaks cannot be tolerated owing to the toxicity of the chemical and the risks to personnel in the area. In such circumstances, not withstanding the fact that the pump or valve may be capable of continuing to operate satisfactorily, the presence of even a minute leak will necessitate shut-down of the supply system and perhaps evacuation of personnel until the leak can be rectified.